Margin stop regulating mechanism with margin stops mounted on control rails



June 20, 1967 L. v. DANIELSON. JR 3,326,347

MARGIN STOP REGULATING MECHANISM WITH MARGIN STOPS MOUNTED ON CONTROL RAILS Filed Sept. 13, 1965 1 X \X\\\\\ f z g a Q INVENTOR LINCOLN V. DANIELSON JR.

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United States Patent MARGIN STOP REGULATING MECHANISM WITH MARGIN STOPS MOUNTED 0N CON- TROL RAILS Lincoln V. Danielson, In, New Britain, Conn., assignor to Royal Typewriter Company, Inc., New York, N.Y., a corporation of Delaware Filed Sept. 13, 1965, Ser. No. 486,781 2 Claims. (Cl. 19763) This invention relates to a margin stop regulating mechanism for typewriters; more particularly it relates to a margin stop regulating mechanism wherein control rails manipulatable to release margin stops from a margin rack bar for movement relative to the margin rack slidably support the margin stops.

In the prior art margin regulating mechanisms, margin stops are slidably mounted on the margin rack bar and released from engagement therefrom for movment relative to the rack bar toward a center post under the influence of .a coiled tension spring or springs by control rails. These arrangements necessitate rather elaborate and expensive margin stop assemblies.

In accordance with the present invention the control rails slidably mount the margin stops thereby permitting the use of margin stops of one piece construction which can be and are preferably made of dimensionally stable high impact plastic.

Accordingly an object of the invention is in the provision of a relatively simplev and inexpensive margin regulator assembly.

Another object of the invention is in the provision of a margin regulator assembly which avoids the necessity for elaborate margin stop assemblies.

A further object of the invention is to provide a margin stop assembly having a minimum of easily assembled elements.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings in which like reference numerals designate like parts throughout the figures thereof and wherein:

FIGURE 1 is a perspective view of the novel margin stop regulating mechanism;

FIGURE 2 is a sectional view taken along lines 22 of FIGURE 1; and

FIGURE 3 is a sectional view taken along lines 3--3 of FIGURE 1.

Referring now to the drawings wherein like reference numerals designate like or corresponding elements throughout the several 'views and wherein a preferred embodiment is illustrated, there is shown in FIGURE 1 a cross frame member generally designated by reference numeral of a typewriter carriage which is supported in a conventional manner for movement relative to a machine frame (not shown), the latter supporting a centrally located upstanding center post 11 and associated line lock and carriage return knock-off paddles 12 and 13.

The ends 14 of the frame member are bent rearwardly and securely support between them as by screws 15 a margin rack bar 16 provided with teeth 17 on its underside. Vertical slots 18 most clearly shown in FIGURE 3 are formed in said ends 14 to receive and to permit vertical movement of identical reversely mounted control or release slides 19 and 21 preferably located on opposite sides of the margin rack bar. The control slides are operable respectively as will hereinafter appear to release left 3,326,347 Patented June 20, 1967 and right margin determining stops generally designated by reference numerals 22 and 23, slidably mounted thereon. Each control slide is provided adjacent its ends with angularly disposed or downwardly inclined parallel slots 24 adapted to receive cross pins 25 anchored by and extending to either side of the margin rack bar which function to cammingly guide the control rails in a vertically downward direction incident to inward lateral movement of the control slides 19 or 21 by an operator thus to disengage the margin stops 22 or 23 from the toothed margin rack bar 16.

As shown in FIGURE 1 there are provided unitary support plates generally designated by reference numerals 26 and 27 secured as by screws or welding to the rear side of the margin rack bar adjacent the left and right ends thereof in the area of the cross pins 25, the latter extending through the body of the support plates. The plates 26 and 27 extend above and below the margin rack bar. The downward extension 28 ofeach plate is bent to extend forwardly and below the margin rack bar as viewed in FIGURES 2 and 3. The forward extensions 29 and 31 serve in cooperation with the center post 11 as final carriage stops should the margin release key be operated to permit carriage movement beyond the set stop elements as is well understood in the art.

The upward extensions of the support plates 26 and 27 serve to anchor control rail return springs and support pins which rotatably mount pulleys. More particularly the upward extension of the left support plate 26 mounts a pin 32 which rotatably supports a pulley 33 in a vertical plane. The upward extension of the right support plate 27 is bifurcated and one leg 34, which mounts a pin 35 to rotatably support a pulley 36, is tilted forwardly of the vertical plane thus to provide clearance for the lower runs of a tension spring 37 trained about the pulleys and attached at its ends to the stops thus to propel the released stops.

The upward extension of the left support plate 26 is formed with a rearwardly extending tab 38 which anchors one end of a biasing spring 39 the other end of which is anchored to the left end of the rear or right margin stop control rail 21 thus biasing the control rail 21 upwardly and outwardly and thus holding the margin stop 23 carried thereby in toothed engagement with the margin rack bar 16. Similarly the other leg 41 of the bifurcated upward extension of the right support plate 27 is formed with a forwardly extending tab 42 which anchors the biasing spring 43 for the forward or left margin stop control rail 19. The geometry is such, it is to be noted, that the biasing springs 39 and 43 are parallel to the camming slots 42 in associated rails to facilitate the return of the control rails upwardly and outwardly.

As clearly shown in FIGURE 1 the margin stops 22 and 23 are of single piece construction having no relatively movable parts and preferably molded from a dimensionally stable high impact plastic material, e.g. Delrin. The margin stops which are identical are slidably mounted oppositely on associated control rails; a slot 44 in the body of each of the margin stops being provided to receive the control rails. Further one side of each margin stop body is formed with a rectangular recess 45 surrounding the top, bottom and one side of the margin rack bar and preferably with a skirt 46 partially closing the recess and surrounding the other side of the bar to prevent front to back movement of the stops relative to the rack due to bowing of the control rails. The lower surface of the rectangular recesses are formed with at least one tooth and may be formed with multiple teeth 47 which engage the teeth of the margin rack; multiple teeth being employed to distribute shock of impact. As noted in FIGURE 1 the recesses are longer than the margin rack in the vertical direction whereby the margin stops may be pushed downwardly relative to the margin rack to etfect tooth disengagement. The upper surface of the left and right margin stop bodies are further formed with spring anchor tabs 48 and 49 which extend rearwardly and forwardly respectively. The tabs 48 and 49 anchor opposite ends of the single coiled tension 37 spring which is trained around the pulleys 33 and 36 thus biasing the margin stops toward the center post 11. Fingers 51 and 52 extending upwardly from the body of the margin stops are provided with indicia marks 53 which in association with a scale 54, indicate the position of the stops relative to the ends of the carriage. The margin stops are further formed with depending portions which extend below the margin rack to provide stop surfaces 55 facing the center post 11 whereby when a stop is released by its associated control rail its movement under the influence of spring 37 will be halted by the center post 11 thus setting the margin stop at a desired location relative to the carriage ends as is well understood in the art. Alternatively the margin stops if adjacent the center post may be moved, subsequent to their release, in response to carriage movement as is well understood in the art.

As is well known, typewriter carriages are provided with margin release mechanism which moves the center post rearwardlyto permit carriage movement beyond a set margin stop. When a carriage has so moved beyond a set margin stop and its motion is subsequently reversed, the stops must be permitted to bypass the center post. Accordingly, the downwardly depending portions of the margin stops are further formed on the sides opposite the stop surfaces 55 with camming projections 56 having cam edges 57 which serve to earn the center post 11 rearwardly to permit this reverse movement.

While a preferred embodiment has been illustrated it is to be understood that the control rails may be both located on one side of the margin rack bar; coiled tension springs 37 individual to each margin stop and anchored at one end to the carriage frame may be employed, in which case the pulleysmay be supported by the control rails thus avoiding the necessity for providing clearance for the lower runs of spring 37 as illustrated, and the support plates may be secured toor formed with the carriage frame.

It should be understood therefore that the foregoing disclosure relates to only a preferred embodiment of the invention and that it is intended to cover all changes and modifications of the example of the invention herein chosen for the purposes of the disclosure which do not constitute departures from the spirit and scope of the invention.

The invention claimed is:

1. Margin release mechanism for a movable typewriter carriage comprising a carriage frame,

a toothed margin rack bar supported at its ends in said frame,

a left and a right margin stop release rail.

means supporting said rails parallel to and for movement relative to said rack bar between non-release and release positions,

springs biasing said rails to non-release positions,

means for moving said rails relative to said rack bar to release positions,

a margin stop having no relatively movable parts slidably mounted on each of said release rails, said stops having at least one tooth integrally formed therewith for engagement with said rack bar, said rails in nonrelease positions holding the margin stops with the teeth thereon engaged with the teeth of said rack bar, rail movement to release positions carrying said margin stops mounted thereon whereby the teeth of said margin stops are disengaged from said rack teeth for movement along said rails,

and spring means for propelling disengaged margin stops along said release rails toward a machine center post.

2. Mechanism as recited in claim 1 wherein said release rails have elongated inclined slots adjacent each end, and wherein said means supporting said rails comprise pins extending from said margin rack bar into said inclined slots, said release rails extending through frame slots which permit downward movement of said release rails by said pins as the rails are moved laterally inwardly to release positions;

References Cited UNITED STATES PATENTS 946,245 1/1910 Mark 19770 1,711,313 4/1929 Garbell 197-70 1,799,182 4/ 1931 Scherer 19763 2,208,367 7/ 1940 Hart 19763 2,302,627 11/1942 Hart 19763 2,316,666 4/1943 Bredimus 19763 2,599,537 6/1952 Barkdoll l97-63 2,699,893 1/1955 Parker et al. 19770 X 2,710,088 6/1955 Sharpe 197-70 2,864,483 12/1958 Carlson 197-63 WILLIAM B. PENN, Primary Examiner.

ROBERT E. PULFREY, Examiner.

E. S. BURR Assistant Examiner. 

1. MARGIN RELEASE MECHANISM FOR A MOVABLE TYPEWRITER CARRIAGE COMPRISING A CARRIAGE FRAME, A TOOTHED MARGIN RACK BAR SUPPORTED AT ITS ENDS IN SAID FRAME, A LEFT AND A RIGHT MARGIN STOP RELEASE RAIL. MEANS SUPPORTING SAID RAILS PARALLEL TO AND FOR MOVEMENT RELATIVE TO SAID RACK BAR BETWEEN NON-RELEASE AND RELEASE POSITIONS, SPRINGS BIASING SAID RAILS TO NON-RELEASE PORTIONS, MEANS FOR MOVING SAID RAILS RELATIVE TO SAID RACK BAR TO RELEASE POSITIONS, A MARGIN STOP HAVING NO RELATIVELY MOVABLE PARTS SLIDABLY MOUNTED ON EACH OF SAID RELEASE RAILS, SAID STOPS HAVING AT LEAST ONE TOOTH INTEGRALLY FORMED THEREWITH FOR ENGAGEMENT WITH SAID RACK BAR, SAID RAILS IN NONRELEASE POSITIONS HOLDING THE MARGIN STOPS WITH THE TEETH THEREON ENGAGED WITH THE TEETH OF SAID RACK BAR, RAIL MOVEMENT TO RELEASE POSITIONS CARRYING SAID MARGIN STOPS MOUNTED THEREON WHEREBY THE TEETH OF SAID MARGIN STOPS ARE DISENGAGED FROM SAID RACK TEETH FOR MOVEMENT ALONG SAID RAILS, AND SPRING MEANS FOR PROPELLING DISENGAGED MARGIN STOPS ALONG SAID RELEASE RAILS TOWARD A MACHINE CENTER POST. 